SPRINGFIELD, Mo.-- -

Young athletes usually have a  quick physical, and then it's on to the playing field.  But a hidden heart defect can lead to sudden tragedy.  Now, parents have a new offense that could catch heart problems before it's too late. 

Kids right here in the Ozarks have died from sudden cardiac arrest. But two women, including one who knows the heartache of losing a child, are on a mission to save lives.

"McKinley was brighter than the sun," says McKinley's mom, Georgia Marshall.

 For McKinley Lambert, there were warning signs.  "She was having trouble at swim meets, and she couldn't swim long distances.  She was having trouble breathing," Marshall says.

It was a hole in McKinley's heart, that doctors repaired in open heart surgery.  But tragically, three years later, a plane crash claimed McKinley and her brother Grayson's lives, along with three others.

"I've struggled with a focus, other than my surviving 11 year old.  It's kind of been tough to try and get out of bed every morning," Marshall says.

But she says a message from her daughter has helped her find new purpose.  "I've had several dreams with the kids, visitation dreams.  I know that they really were there with me," Marshall says.  "She said mom, you're supposed to help other kids.  And she said, everything I went through, all the trouble I went through, the nine hours open heart surgery."

Unlike McKinley's heart, many have no warning.  "He was just a normal, roughhouse kid," says Steve Varney.  His son, Forrest Varney, was an athlete practically all of his 17 years.

"He was very active in sports and just from go-cart racing, football, basketball, baseball, about everything," Varney says.

But at an early morning basketball practice, Forrest collapsed.  "They just never did revive him, and they had all the latest equipment that most schools have," Varney says.  "I believe everybody did everything they could."

Forrest's heart stopped.  "They said it was an enlarged heart and congestive heart failure," Varney says.

"That's what I'm hoping, along with this company, to try to help save some families the grief and the pain and agony of having to go through this," says Marshall.

 "She had called me and said, I think this is something that I need to do," says Tammy Cowan, co-founder of Midwest Heart Check.

It's a cause that had also been tugging on Cowan's heartstrings.  "We had heard that there were a couple young students that had died from sudden cardiac death in the area, and there wasn't anybody doing sudden cardiac death screenings," Cowan says.

Already having the ultrasound equipment for her business, Cowan was soon set up for heart screenings.  They include three blood pressure measurements, a 12 leed electrocardiogram, which measures the electrical pulses given out by the heart, and an echo cardiogram, which uses ultrasound to closely examine the heart.

"We look at all of the valves, make sure they're in working order, make sure there's no quote, unquote, holes in the heart," says Cowan.

Kristy Larangeira wanted her heart checked out following a recent episode while training for her first marathon.  "I started feeling really ill, dizzy, and I made it across the street, and I thought, I need to stop right now or something bad's going to happen.  So I went ahead and laid down, and I passed out for a few seconds," says Larangeira.

"This is her regurgitation, so when the valve closes, she's got a little, pssh," Cowan pointed out on the echo cardiogram.  The screening, which is read by a cardiologist, found Larangeira has a mild heart murmur.

"I do want to learn more about it," Larangeira says.   She's glad to have the information without a hefty hospital bill.  "If it cost 1,000 dollars, I wouldn't have gone on my own," says Larangeira.

Midwest Heart Check is doing the screenings for $150 dollars.   "We know that there are people in the Ozarks that can't afford to go and get a $1,200 echo and a $75 ECG," says Cowan.

"I think they need to have a deeper check than just your regular physical to participate in sports," says Varney.

"It doesn't take much to save a life," Cowan says.

They hope to screen as many student athletes as possible and catch heart problems before it's too late.  "I think he maybe made a point  that something needs to be done," says Varney.

Marshall says, "It was just, 'We had to do this mom, and this is what you're supposed to do.'  I understand now."

Midwest Heart Check is completely mobile and hopes to even take their equipment into schools to do screenings.  The Grayson-McKinley Memorial Foundation is raising money to help families that can't afford the $150 screening fee.  Click the links above to learn more, or to schedule a heart screening, call (417)861-0071